Unity3D 相机跟随主角移动

using UnityEngine;
using System.Collections;

public class camerafollow : MonoBehaviour {
    //主摄像机跟随主角一起移动
    public float xMargin = 1f;
    public float yMargin = 1f;
    public float xSmooth = 8f;
    public float ySmooth = 8f;
    public Vector2 maxXandY;
    public Vector2 minXandY;
	// Use this for initialization
    private Transform player;
	void Start () {
//这里获得是绑定的主角，需要一起跟随移动，就要获得主角的属性
        player = GameObject.FindGameObjectWithTag("pk_0").transform;
        maxXandY.x = 10; maxXandY.y = 10;
	}
    bool checkxmargin() {
        return Mathf.Abs(transform.position.x - player.position.x) > xMargin;
    }
    bool checkymargin() {
        return Mathf.Abs(transform.position.y - player.position.y) > yMargin;
    }
	// Update is called once per frame
	void Update () {
        Trackplayer();
	}
    //跟踪主角
    void Trackplayer() {
        float targetx = transform.position.x;
        float targety = transform.position.y;
        if (checkxmargin())
        {
            targetx = Mathf.Lerp(transform.position.x, player.position.x, xSmooth * Time.deltaTime);

        }
        if (checkymargin())
        {
            targety = Mathf.Lerp(transform.position.y, player.position.y, xSmooth * Time.deltaTime);
        }
        targetx = Mathf.Clamp(targetx, minXandY.x, maxXandY.y);
        targety = Mathf.Clamp(targety, minXandY.y, maxXandY.y);
        transform.position = new Vector3(targetx, targety,transform.position.z);
    }
}